diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index c05d48f88596..f6cf728ee32a 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -628,10 +628,12 @@ iopgtable_store_entry_core(struct omap_iommu *obj, struct iotlb_entry *e)
 		break;
 	default:
 		fn = NULL;
-		BUG();
 		break;
 	}
 
+	if (WARN_ON(!fn))
+		return -EINVAL;
+
 	prot = get_iopte_attr(e);
 
 	spin_lock(&obj->page_table_lock);